Joint seal



March 10, 1964 .1. M. GRAHAM JOINT SEAL Filed Sept. 2, 1960 A T TORNE Y United States Patent 3,124,947 JOINT SEAL John M. Graham, 1808 E. Yale St, Phoenix, Ariz. Filed Sept. 2, 1960,5121. No. 53,806 1 (Ilaim. (Cl. 9418) This invention relates to expansion joints for masonry masses, such as concrete slabs, and especially to resilient means for sealing such expansion joints for the purpose of preventing the penetration of water thereinto.

it is an important object of this invention to provide an improved expansion-joint sealing structure which can be easily inserted into the gap of an existing expansion joint to positively exclude the entrance of moisture thereinto, and which seal has sufficient resilience to permit it to expand and contract to follow variations in the width of the gap.

Another important object of the invention is to provide a resilient joint sealing structure which is free to expand and contract with changes in the gap width due to atmospheric temperature variations, without appreciably affecting the freedom of motion at the joint. The seal when in place leaves a large proportion of the gap open and free of masses which would otherwise tend to restrict expansive and contractive movements at the joint.

Still a further object of the invention is to provide an elastic seal which cooperates with the structure of the masonry in the vicinity of the gap at the joint and is supported thereby despite variations of the width of the gap as the concrete expands and contracts. The elastic strip employed for this purpose has a convex arched portion supporting an elastic sealing compound located in the gap above the strip. The arched form of the strip adds strength and resilience to its support of the said sealing compound, thereby tending to urge the compound upwardly in the gap to assist it in recovering from forces displacing the compound vertically downwardly.

Other objects and advantages of my invention will be come apparent during the following discussion of the drawing, wherein:

FIG. 1 is a cross-sectional view taken through two adjacent concrete masses having an expansion gap therebetween containing the present sealing structure in place;

FIG. 2 is a sectional view similar to FIG. 1 and showing a modified type of elastic supporting strip;

FIG. 3 is a cross-sectional view illustrating a further modified form of the invention;

FIG. 4 is a perspective view illustrating one half of the joint and the seal shown in FIG. 3;

PEG. 5 is a perspective view of the elastic strip used in FF. 2; and

FIG. 6 is a perspective view of a modified form of elastic strip suitable for use in the joint illustrated in FIG. 2.

Referring now to the drawings, like elements in the several views are designated by similar reference characters.

FIGS. 1 and 2 illustrate two opposed concrete slabs 10 and Ill separated from each other by a gap 12, the width of which gap varies depending upon the temperature of the concrete slabs due to thermal expansion and contraction thereof. The embodiment shown in FIG. 1 includes an arched resilient strip 13, preferably made of rubber or neoprene, or of some suitable plastic sheet material which is preferably molded or formed flat and then distorted into the arched condition shown in FIGS. 1 and 3 when it is inserted in the gap between the two concrete slabs. Thus, when the slabs Ill and 11 expand or contract so that the width of the gap 12 varies, the resilient strip 13 will change its arch in the gap so as to substantially maintain its position therein. In the embodiments shown in FIGS. 1 and 2, the concrete slabs are provided with recesses in their ends, respectively labeled 14 and 15, the reference numeral leader lines being drawn to the shoulders at the lower ends of the recesses against which the vertically disposed side portions 13a and 13b of the resilient strip 13 abut. Since these side portions 131: and 13b rest on the shoulders at the lower ends of the recesses 14 and 15, it will be apparent that the resilient strip can not shift downwardly in the recesses. The side portions 13a and 131) are joined by an arched portion of the strip 13c, and this arched portion effectively closes the gap 12 and supports a sealing compound 16 such as soft tar or asphalt which yields or spreads with the movements of the slabs during their contraction and expansion.

The recesses 14 and 15 are, of course, formed while the concrete is being laid. After the concrete has been laid, the resilient strip 13 is then deformed and forced downwardly into the gap so that it expands and is confined in inverted U-shaped orientation in the two recesses 14 and 15. The sealing material 16 is subsequently heated to a molten state and poured into the gap on top of the arched portion 13c of the supporting strip 13.

In the embodiment shown in FIG. 2 a modified resilient strip is used, this strip taking the form of a tubular member 17 which member can also be seen in FIG. 5. The member 17 can either be formed in oval shape, as shown in FIG. 5, or can take the shape of a cylindrical member 17', as shown in FIG. 6. This cylindrical body 17' would, of course, take the oval shape of the strip 17 shown in FIG. 2 when it is inserted in the recesses 14-, 15 in the gap 12 between the concrete slabs ill and 11. The structure and functioning of this strip 17 is rather similar to the strip 13 to the extent that it has vertically disposed side portions 17:: and 1712 joined by an arched upper portion 17c upon which the sealing compound 16 is poured and supported.

The tubular forms 17 as shown in FIG. 5, and 17' as shown in FIG. 6, have an additional advantage over the U-shaped strip 13 shown in FIGS. 1 and 3, because in the tubular members the lower arcuate portion 17d as shown in FIG. 2 maintains the side portions 17a and 17b separated so that they positively engage the shoulders at the lower edges of the recesses 14- and 15. In other words, where a U-shaped member 13 is used as shown in FIG. 1, it is possible for the lowermost edges of the side portions 13a and 13b to approach each other, as by curling, and thereby come out of engagement with the shoulders at the lower edges of the recesses 14 and 15.

The embodiment of FIG. 3 tends to avoid this possibility since the lower edges of the U-shaped strip 13 engage an arched upright member 18 which, because of its arched upper portion 18a, tends to spread the lower edges of the vertical portions 13:: and 13b outwardly against the concrete slabs Ztl and 21, which have been provided with different reference characters from those designating the concrete slabs in FIGS. 1 and 2 because of the fact that the slabs 20 and 21 do not have recesses in their adjacent end surfaces defining the gap 22. The sealing compound 23 is poured into the gap 22. in FIG. 3 so that it rests upon the U-shaped strip 13 in substantially the same manner as illustrated in FIGS. 1 and 2. The structure of the joint can be seen best in the perspective view of FIG. 4 which illustrates the same embodiment as the cross-sectional view of FIG. 3. Inasmuch as the concrete slabs 2t) and 21 would be supported on the surface therebelow, such as a ground surface or a supporting platform, it is to be understood that the U-shaped supporting members 13 are prevented from creeping downwardly in the gap 22 by the same surface (not shown) which supports the concrete slabs 2t) and 21.

In all of the various embodiments illustrated in this disclosure, it is important to note that the joint provided by any one of the embodiments is substantially open." In other words, except for the sealing compound 16 or 23 located in the top of the gap between the two concrete slabs, which material is easily deformed, the joint is almost entirely open, meaning that there is nothing in the lower portion of the gap, and meaning that the resilient strip has an open center so that it is also very free to contract and expand.

The present sealing means are obviously applicable to other expansion joints, such as joints made between metal members, or joints between the armored ends of concrete or other masonry structures. The present invention is therefore not to be limited to the exact forms shown in the drawings, for obviously changes may be made therein within the scope of the claim.

I claim:

An expansion joint and structure for sealing the top of a gap between masonry slabs, comprising opposed end surfaces on the slabs spaced apart and defining a gap therebetween, the end surfaces each having a continuous recess widening the gap at a location above its bottom and below its top and providing opposed shoulders in both end surfaces of the slabs mutually spaced above the bottom of the gap; a continuous elongated resilient sheet material member having a wall thickness which is small as compared with the width of the gap, and bowed in the shape of an arch of inverted U-shaped cross-section, and

having a substantially semi-cylindrical upper arched portion with depending parallel side portions yleldably pressing against the surfaces located between the opposed shoulders, said depending portions being confined by said opposed shoulders and supported thereby, said side portions being separated from each other by spacing greater than said wall thickness and the portion of the gap below said member remaining substantially open; and an elastic sealing compound initially flowed into and filling the space between the end surfaces of the slabs above the semi-cylindrical portion of said member and supported thereby substantially level with the tops of said end surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 1,885,391 Thompson et a1 Nov. 1, 1932 1,956,809 Robertson May 1, 1934 1,965,403 Alvey July 3, 1934 2,138,817 Jacobson Dec. 6, 1938 2,156,681 Dewhirst et al. May 2, 1939 2,220,628 Stedman Nov. 5, 1940 2,315,588 Brickman Apr. 6, 1943 2,365,550 Heltzel Dec. 19, 1944 2,400,493 Fischer May 21, 1946 3,060,817 Daum Oct. 30, 1962 

